title: Epinephrine improves 24-hour survival in a swine model of prolonged ventricular fibrillation demonstrating that early intraosseous is superior to delayed intravenous administration.
abstract: BACKGROUND
  Vasopressors administered IV late during resuscitation efforts fail to improve survival. Intraosseous (IO) access can provide a route for earlier administration. We hypothesized that IO epinephrine after 1 minute of cardiopulmonary resuscitation (CPR) (an "optimal" IO scenario) after 10 minutes of untreated ventricular fibrillation (VF) cardiac arrest would improve outcome in comparison with either IV epinephrine after 8 minutes of CPR (a "realistic" IV scenario) or placebo controls with no epinephrine.
  
  
  METHODS
  Thirty swine were randomized to IO epinephrine, IV epinephrine, or placebo. Important outcomes included return of spontaneous circulation (ROSC), 24-hour survival, and 24-hour survival with good neurological outcome (cerebral performance category 1).
  
  
  RESULTS
  ROSC after 10 minutes of untreated VF was uncommon without administration of epinephrine (1 of 10), whereas ROSC was nearly universal with IO epinephrine or delayed IV epinephrine (10 of 10 and 9 of 10, respectively; P = 0.001 for either versus placebo). Twenty-four hour survival was substantially more likely after IO epinephrine than after delayed IV epinephrine (10 of 10 vs. 4 of 10, P = 0.001). None of the placebo group survived at 24 hours. Survival with good neurological outcome was more likely after IO epinephrine than after placebo (6 of 10 vs. 0 of 10, P = 0.011), and only 3 of 10 survived with good neurological outcome in the delayed IV epinephrine group (not significant versus either IO or placebo).
  
  
  CONCLUSIONS
  In this swine model of prolonged VF cardiac arrest, epinephrine administration during CPR improved outcomes. In addition, early IO epinephrine improved outcomes in comparison with delayed IV epinephrine.
authors.affiliation: The Sarver Heart Center at University of Arizona College of Medicine, Tucson, Arizona, USA. zuercher@email.arizona.edu
authors.forename: Mathias
authors.initials: M
authors.lastname: Zuercher
authors.forename: Karl B
authors.initials: KB
authors.lastname: Kern
authors.forename: Julia H
authors.initials: JH
authors.lastname: Indik
authors.forename: Michael
authors.initials: M
authors.lastname: Loedl
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Hilwig
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ummenhofer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Ewy
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004837:Epinephrine / Q000008:administration & dosage*; D005260:Female; D017148:Infusions, Intraosseous; D007262:Infusions, Intravenous; D008297:Male; D010865:Pilot Projects; D011897:Random Allocation; D015996:Survival Rate / Q000639:trends; D034421:Sus scrofa; D013552:Swine; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000401:mortality
chemical_list: D004837:Epinephrine